Hypertension: Often Symptomless, Always WorrisomeHypertension is a leading cause of cardiovascular d

Hypertension is a leading cause of cardiovascular disease (CVD)—the most significant factor, by some measures. It certainly ranks among the top three; the others are high LDL cholesterol levels and smoking. All three of these risk factors are considered “modifiable.” (Examples of non-modifiable risk include age and family history.) High blood pressure contributes to the development of stroke, heart attack, heart failure, and kidney disease. In the United States, it directly accounts for about 60,000 deaths a year and contributes to another 300,000.

Moderate exercise is a major combatant against hypertension. Endurance exercise in particular helps because during it, the heart pumps harder to provide oxygen-rich blood to the muscles, while vessels dilate to make room for the increased flow. When we complete our bout of exercise, the heart rate returns quickly to normal (or even below), but the blood vessels continue to remain dilated for several hours. In fact, average blood pressure values in men with mild hypertension remain reduced by between 6 and 9 mm Hg for over 12 hours after just 30 minutes of low- or moderate- intensity endurance exercise. People who exercise an hour a day, then, are in a near-constant state of reduced blood pressure.

By contrast, resistance exercise, particularly vigorous weight lifting, can cause sharp increases in blood pressure. Patients with atherosclerotic coronary arteries may induce cardiac events with this type of exercise. Still, it is not accurate to call exercise the cause of such events; it is occasionally the trigger.

How it Hurts. When arteries are brittle, the increased heart rate forces blood as if through an old, frail garden hose; rather than expanding to mitigate the increased pressure, vessels can erupt or dislodge dangerous plaques that swim downstream and cause clots leading to myocardial infarction or stroke. If your blood pressure is already higher than is considered healthy, the problem is escalated even further. (Hypertension is diagnosed when systolic blood pressure reaches 140 mm Hg and/or when diastolic reaches or exceeds 90 mm Hg.)

Still, prior vigorous exertion is found in just 5% of people who suffer myocardial infarction. Between 6 and 17% of all sudden deaths are considered exercise related. The vast majority of exertional heart attack deaths documented people who were splitting wood, gardening, or heavy lifting or pushing (70%). About 30% were jogging or playing racquet sports. That is, their usual frequency of vigorous exertion was a major factor—it was over 50 times a factor for those usually sedentary as for those who regularly exercise.

Studies in fact show that the risk of inactivity is similar in magnitude to that of these three well-accepted CVD risk factors.

A Subtle Danger. A silent condition like high blood pressure is sneaky. It generally doesn’t cause any outward signs or symptoms, and yet it relentlessly causes problems in the arteries, heart, kidneys, and elsewhere. But it isn’t considered a disease. It’s a sign, more than anything, that something is wrong with the body.Perhaps because of all the ways hypertension interferes with health, the average life span for people with it is five years shorter than it is for those with normal blood pressure.

A team of Spanish researchers has tallied up another hidden drain of high blood pressure—its effect on survival and rehospitalization after someone is admitted for a heart problem. The researchers looked at 1,007 men and women admitted to the hospital over a 10-month period for any potentially heart-related problem. These ranged from chest pain and fainting to heart attack, heart failure, atrial fibrillation, and pericarditis. In this group, 69% had been diagnosed with high blood pressure before being admitted to the hospital.

Each person was followed for one year. At the end of that time, 17% of those with high blood pressure had died, compared with 9% of those with normal blood pressure. Rehospitalization for a cardiac problem followed the same pattern: 31% of those with high blood pressure were rehospitalized, while only 18% of those without it were.

What We Can Do. It is possible to blunt the effects of hypertension by keeping blood pressure in check with medications and lifestyle choices. Preventing it from getting started is even better.The National Heart, Lung, and Blood Institute; the Centers for Disease Control and Prevention; and the American Heart Association offer these recommendations:

Control your weight.

Exercise regularly.

Follow a diet that is rich in fruits, vegetables, and whole grains, which help remove sodium from the body.

Limit sodium intake to under 2,300 milligrams a day (one teaspoon of salt), and get plenty of potassium (at least 4,700 mg per day) from fruits and vegetables.

Drink alcohol in moderation, if at all.

Reduce stress.

Check your blood pressure.

The combination of chronic hypertension, sudden spikes in blood pressure, and plaque-narrowed and brittle arteries is dangerous. It is also indicative of a lack of regular, moderate, endurance activity in your lifestyle. Pathologist and early running advocate Tom Bassler, MD, who died in December at the age of 79, noticed long ago that people on his autopsy table who had springy, youthful Achilles tendons tended to also have springy, youthful coronary arteries. From his unique perspective, a correlation was undeniable. Regular, moderate exercise keeps blood vessels and coronary arteries resilient and flowing freely, meaning that blood pressure has a decreased chance of building up to dangerous levels. For more on Bassler’s theories about the benefits of regular endurance activity, see Is a Mile a Mile? in this issue.